Here's a hard one;

It's in the episode where cartman is trying to find out who his dad is. Some city members end up stuck in the school with the crew of americas most wanted (cause of a snow storm) and decide to eat each other after only one day. The song is towards the end if I remember right the maire says something about "we're finally free" to what jimbo responds: at what cost maire...at what cost... The song begins with a camera zoom out of the school.

If some of you hear it - you might recognize it. It's tragic, sad type of melody. It's not an EDM song.

EDIT: The episode might be named Cartman's mom is still a whore